Magnetic cross tees

ABSTRACT

An elongated metal grid runner for a suspended ceiling, the grid runner having a cross-section with an upper hollow reinforcing bulb, a vertical web extending below the bulb, and lower flange elements extending laterally from opposite sides of the web, the length of the grid runner being less than about 9′, a permanent magnet disposed on each end of the grid runner at its flange elements, the magnet being adapted to overlie and be attracted to a horizontal leg of a steel wall angle to thereby releasably retain the grid runner in position on the wall angle.

BACKGROUND OF THE INVENTION

The invention relates to building construction and, in particular, tosuspended ceilings.

PRIOR ART

Building areas such as corridors or hallways and small rooms typicallyhave short spans between opposing walls. Frequently, the space abovesuch areas is utilized for air ducts and other utilities. It can bedesirable or mandatory that a suspended ceiling be provided withremovable panels to allow ready access to the space or plenum above aceiling. The existence of primary air ductwork and other objects in theoverhead space often makes hanging conventional suspension wiresdifficult or prohibitive. Any solution for constructing a suspendedceiling should avoid the need for extensive and/or specialized laborand, ideally, will actually reduce the labor and skill requirements.

SUMMARY OF THE INVENTION

The invention resides in a short span suspended ceiling system with aunique grid runner and wall angle attachment. The attachment is made bypermanent magnets carried on the ends of the grid runners that extendperpendicularly to the wall angles. The magnets are arranged to bestrongly attached to the horizontal leg of a steel wall angle. The wallangles are of sufficient strength to support the grid runners and theceiling tiles carried on the grid runners. The invention can be embodiedwith the type of grid runner that has a box section with an open slot onits bottom face. In this case, a magnet is inserted in the box sectionat each end of the grid runner. The grid runners are cut to a lengthsuch that their ends and the associated magnets overlie the horizontallegs of oppositely facing wall angles.

The invention is useful with the more common style of grid runner or teewith flat flanges at their lower sides. In such a case, the ends of thetees can be modified by displacing material from a web above the flangefor reception of a magnet.

With the invention there is no need to index the spacing of a runneralong the length of the wall angles. The position of the runners, forexample, can be determined by the width of the ceiling tiles or panelsas they are being installed or by lengths of short cross runners if thelatter are used. The grid runners of the invention can be used intrapped modules where the grid runner ends are supported on elementsthat, like the wall angles, cannot be deflected or rotated laterally toreceive or release a connector designed to extend through such anelement, for example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary isometric view of a short span suspended ceilingsystem constructed in accordance with the invention;

FIG. 2 is a fragmentary isometric view of a grid runner constructed inaccordance with the invention shown in relation to supporting wallangles; and

FIG. 3 is a fragmentary isometric view, similar to FIG. 2, showing analternative grid runner profile.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A short span suspended ceiling is represented at 10. The ceiling 10 andwalls 11 can represent, for example, a corridor or hallway thattypically is of a length substantially greater than its width. However,the invention can be used for the ceiling of a small room. The ceiling10 comprises a plurality of spaced parallel grid runners 12, extendingtransversely to the length of the corridor, and rectangular ceilingpanels or tiles 13 carried by the grid runners 12.

On the walls 11, at ceiling height is a pair of opposed, elongated wallangles 14. The wall angles 14 are made of sheet steel which may be hotdipped galvanized and painted. Each wall angle 14 has a horizontal leg16 and a vertical leg 17.

The illustrated style of grid runner in FIGS. 1 and 2 is of a knownstyle, disclosed for example in U.S. Pat. No. 4,535,580. This style ofgrid runner has a hollow box-like structure 21 at its lower side. Theprofile of the grid runner 12 includes an upper hollow reinforcing bulb22, a vertical web 23, and two inwardly facing C-shaped flanges 24 thatmutually form the box section or structure 21. The flanges 24 are at thelowermost part of the runner 12 and are spaced from one another to leavea gap or slot 26. Typically, the grid runner 12 is roll-formed of sheetsteel that can be hot dipped galvanized and painted.

The invention is particularly useful in arrangements where the gridspans a distance of between about 5′ to about 9′. At the longer spanswithin this range, the grid runner can be made of relatively heavy gaugestock and/or can be reinforced by adding layers of sheet steel to thereinforcing bulb 22 and/or can be increased in height to make itstronger. The length of a grid runner 12 is cut to provide moderateclearance with the inside surfaces of the vertical legs 17 of theopposed wall angles 14.

A permanent magnet 27 is assembled at each end of a grid runner 12 intothe flange formed box 21. The magnet 27 will tend to hold itself inposition in the flange box 21 at which it is placed. An adhesive,indicated at 28, can be used to secure a magnet in position, if desired.

The ceiling tiles 13 can be standard commercially available unitstypically with nominal rectangular face dimensions of 2′×2′, 2′×4′, or2-½′×5′, or metric equivalents thereof. The ceiling 10 can beconstructed by initially installing the wall angles 14 on opposite walls11 at the desired height. Wall angles, not shown, can be similarlyinstalled at the end or ends of the corridor. Alternatively, a gridrunner or runners 12 can be used for starting and ending at thebeginning or end of a hallway. Starting at one end of a corridor orhallway, the walls 11 or wall angles 14 can be marked to indicate thedesired centers for the grid runners 12. Normally, the runners will bearranged perpendicularly to the walls. Typically, the grid runners 12will be positioned on 2′ centers. The magnets 27, being disposeddirectly over the horizontal legs 16 of the wall angles 14, willreleasably hold the grid runners 12 in the positions at which they aremanually set. The tiles 13 can be laid on the grid runners 12 in aconventional manner by manipulating them through the plane of the gridrunners 12. If desired, the steps of laying out the centers of the gridrunners along the respective walls angles 14 can be omitted and the gridrunners 12 can be roughly positioned on the wall angles. Thereafter,successive grid runners 12 can be more precisely positioned using a rowof installed tiles 13 as a gauge. From the foregoing, it will beunderstood that the position of a grid runner 12 along a wall angle 14is not dictated by locating features on the wall angle. The magnets 27will hold their respective grid runner ends firmly, but releasably, inplace on the wall angles 14. The grid runners are installed in aso-called “trapped module” where there is no horizontal freedomavailable for the wall angles 14.

The broken lines 31 in FIG. 1 represent abutting edges of panels 13 orlocations of cross runners aligned with the walls 11. As isconventional, the panels or tiles 13 can be cut to fit the width of thecorridor. If desired, the grid runners 12 can be provided with regularlyspaced slots along their lengths. Such slots, in a conventional manner,can receive connectors on the ends of the cross runners as is known inthe art and shown, for example, in aforementioned U.S. Pat. No.4,535,580.

It will be understood that the ceiling components comprising the wallangles 14, grid runners 12, and tiles 13, can be installed in locationswhere there is little or essentially no overhead clearance available inthe space above the ceiling 10. Moreover, a high level of access isafforded to the space above the ceiling 10 since an installed gridrunner 12 can be moved out of position by simply lifting the tiles 13 itsupports and shifting it along the wall angles 14. A grid runner 12 canbe completely removed from the ceiling 10 with intuitive motion, notrequiring special technique and not requiring any movement of thesupporting wall angles 14. Temporary removal of one or more grid runners12, as well as associated ceiling tiles 13 afforded by the invention,gives full unobstructed access to the plenum above the ceiling. The riskof damaging these displaced ceiling parts is reduced where work is beingconducted through the plane of the ceiling.

FIG. 3 illustrates the invention applied to a common form of grid runnerthat has the general shape of an inverted tee. The grid runner or tee36, as is typical, is roll formed of sheet steel and includes a hollowupper reinforcing bulb 37, a vertical web 38, and a lower flat flange39, extending on opposite sides of the web. The web 38 is notched ateach end of the grid runner 36 to receive a respective permanent magnet27. To supplement the attractive force on the grid runner 36, the magnetcan be adhesively secured to the runner and/or the notch, designated 41,can be configured to mechanically hold the magnet in position. The gridrunner or tee 36 can be used in the manner described above in connectionwith the grid runner 12.

It should be evident that this disclosure is by way of example and thatvarious changes may be made by adding, modifying or eliminating detailswithout departing from the fair scope of the teaching contained in thisdisclosure. The invention is therefore not limited to particular detailsof this disclosure except to the extent that the following claims arenecessarily so limited.

1. An elongated metal grid runner for a suspended ceiling, the gridrunner having a cross-section with an upper hollow reinforcing bulb, avertical web extending below the bulb, and lower flange elementsextending laterally from opposite sides of the web, the length of thegrid runner being less than about 9′, a permanent magnet disposed oneach end of the grid runner at its flange elements, the magnet beingadapted to overlie and be attracted to a horizontal leg of a steel wallangle to thereby releasably retain the grid runner in position on thewall angle.
 2. A grid runner as set forth in claim 1, being roll-formedsheet metal.
 3. A grid runner as set forth in claim 1, wherein themagnets are adhesively attached to the grid runner.
 4. A grid runner asset forth in claim 1, wherein the flange elements form a hollow box andthe magnets are disposed in the box.
 5. A grid runner as set forth inclaim 1, wherein the web at the ends of the grid runner is displacedfrom a zone and the magnets are situated in the zones.
 6. A suspendedceiling grid comprising a pair of oppositely facing wall angles securedto respective walls, the wall angles being formed of sheet steel andhaving vertical and horizontal legs, a plurality of runners spanning thearea between the wall angles and being supported on the horizontal legsof the wall angles, the runners being in spaced parallel relation toeach other and perpendicular to the wall angles, the runners havingpermanent magnets on their ends overlying the horizontal leg of therespective wall angle serving to releasably hold the runners in place onthe wall angles.
 7. A suspended ceiling grid as set forth in claim 6,wherein the grid runners are of the type having a hollow box-likeformation at their lower sides, the magnets being disposed in saidbox-like formation.
 8. A suspended ceiling grid as set forth in claim 6,wherein the grid runners have the general shape of an inverted tee withan upper hollow reinforcing bulb, a vertical web below the bulb andflange elements extending laterally from opposite sides of a lower edgeof the web, the web being displaced at the ends of the runners toaccommodate the magnets.